Portfolio Company Jobs


Back-End Engineer (Experimentation)



Software Engineering
Kiev, Ukraine
Posted on Monday, December 11, 2023

At Preply, we are unlocking human potential through learning.

We believe learning with a great tutor is life-changing. That’s why we match online tutors from across the globe with learners and empower them to create live language classes with AI-powered tools and learning materials. This is how we deliver progress, create engagement and keep our global community of learners motivated. So far, over 32,000 tutors have given more than 15 million lessons to learners from over 175 countries.

Preply Engineering Team provides the tools to help unlock human potential through learning.

We work primarily with Python/Django to build scalable and robust applications. We implement A/B tests to prove the value of our initiatives and improve our product based on data and students and tutors feedback. As part of our commitment to ensuring high-quality products, we prioritize monitoring and metrics analysis to identify areas for optimization and ensure our services are performing at their best. Our team is made up of talented engineers who are passionate about solving complex problems and developing innovative solutions to drive our company's success.

At Preply, we release our product 50-60 times per day by leveraging top-notch CI/CD processes. As a fast-growing company we have diverse technical challenges (sometimes we even write about them on our Engineering Blog) that will allow you to develop your skills at scale.

Meet the team!

Here at Preply, we a/b test most of our changes on production, both product and technical, before scaling them to all customers. Experimentation Squad owns the whole infrastructure that is used to make those business-vital decisions.

You, as a part of Experimentation Squad, will develop systems that are used by all product and platform squads in their daily work in the decision-making process; tackle problems that occur in highly loaded systems, such as cross-experiment correlation, data consistency, event deduplication, etc.; design and monitor architecture in a way that will guarantee stability and reliability in the highly variative environment where 100+ developers deploy production 60+ times a day.

This position is in the intersection of Data, Development & Research. You’ll use Data skills to write ETLs, setting up alerts on data. Research skills will help to dive deeper in the data and experiments, to identify what is going wrong, how to fix it and how to prevent it from happening again in the future. Finally, you’ll use Dev skills to automate routine, iterate on our A/B system core and A/B visualization tool.

What you’ll be doing:

  • Establish credibility with the quality of the a/b testing system
  • Own Data pipelines and ensure Data consistency
  • Support & develop a/b testing visualization tools
  • Collaborate with product teams to help them tackle issues with a/b testing
  • Introduce a/b testing into new areas (Marketing, etc.)

What you need to succeed:

  • Strong knowledge of Python, at least 5+ years experience.
  • Strong hands-on skills in SQL.
  • Deep proficiency with databases (understanding internal mechanisms).
  • Experience working with web-frameworks, like Django or Flask.
  • Addiction to quality control (we don’t have QA/QC engineers).
  • Proven experience in leading projects and teams.
  • A passion for analyzing data to inform decisions.
  • Readiness to take responsibility of systems (ownership).
  • Desire to solve business problems instead of just doing tasks.

Why you’ll love it at Preply:

  • Open, collaborative, dynamic and diverse culture.
  • Generous monthly allowance for lessons on Preply.com .
  • Learning & Development budget, including time off for your self-development.
  • Competitive financial package with equity, leave allowance and health insurance.
  • Access to free mental health support platforms.
  • Flexible set-up with the option of paid relocation to Barcelona, or working remotely within a close time zone.
  • Opportunity to shape the lives of learners and tutors from over 175 countries through language learning and teaching.

Our Principles

  • Care to change the world - We are passionate about our work and care deeply about its impact to be life changing.
  • We do it for learners - For both Preply and tutors, learners are why we do what we do. Every day we focus on empowering tutors to deliver an exceptional learning experience.
  • Keep perfecting - To create an outstanding customer experience, we focus on simplicity, smoothness, and enjoyment, continually perfecting it as every detail matters.
  • Now is the time - In a fast-paced world, it matters how quickly we act. Now is the time to make great things happen.
  • Disciplined execution - What makes us disciplined is the excellence in our execution. We set clear goals, focus on what matters, and utilize our resources efficiently.
  • Dive deep - We leverage business acumen and curiosity to investigate disparities between numbers and stories, unlocking meaningful insights to guide our decisions.
  • Growth mindset - We proactively seek growth opportunities and believe today's best performance becomes tomorrow's starting point. We humbly embrace feedback and learn from setbacks.
  • Raise the bar - We raise our performance standards continuously, alongside each new hire and promotion. We build diverse and high-performing teams that can make a real difference.
  • Challenge, disagree and commit - We value open and candid communication, even when we don’t fully agree. We speak our minds, challenge when necessary, and fully commit to decisions once made.
  • One Preply - We prioritize collaboration, inclusion, and the success of our team over personal ambitions. Together, we support and celebrate each other's progress.

Diversity, Equity, and Inclusion

Preply is committed to creating a diverse and inclusive environment where people from all backgrounds can thrive. Different opinions and viewpoints are key ingredients in our success as a multicultural Ed-Tech company.

Preply will consider all applications for employment without regard to race, color, religion, gender identity or expression, sexual orientation, national origin, disability, age or veteran status. Together, we are The World Class.